Day 1: shhrukrishna temple/malpe beach and St Mary island
day 2: dharmasthala and kukke subrahmany
day 3 kudroli temple, pilikula dhama, kadri manjunatha, mangladevi temple and light house
Day 1 - Udupi: Sri Krishna temple, Malpe beach (there are some activities which you can do now here), St. Mary's island, Kaup light house if time permits Day 2 - Mangalore: Kudroli and Mangaladevi temple, Panambur beach, Suratkal NITK light house Day 3 - you can plan according to your mode of transport and destination. few options are Sringeri and Dharmasthala belt, Sakaleshpura or Madikeri
A few temples but if ou are are in Bangalore then surely visit a restaurant called "Machhali".
trust me you won't be disappointed. Try crab ghee roast.